Calcareous nannofossils of ODP Sites 149-897 and 149-901@en

Mesozoic calcareous nannofossil assemblages recovered during Ocean Drilling Program Leg 149 from the Iberia Abyssal Plain off the coast of Portugal were examined to determine the age of the rifting processes that affected the western Iberia Margin.
Dark carbonaceous claystones (black shales) recovered from Site 901 contain highly diverse and abundant Tithonian calcareous nannofossil assemblages. Careful examination and documentation of this material has extended the ranges of numerous Jurassic and Cretaceous species and detailed a significant Late Jurassic assemblage turnover observed in the calcareous nannofossil record. […]

本研究对葡萄牙外海伊比利亚深海平原通过大洋钻探计划（Ocean Drilling Program, ODP）第149航次采集获得的中生代钙质超微化石（calcareous nannofossil）组合开展了系统分析，旨在明确影响伊比利亚西部陆缘的裂谷作用的形成年代。
从901站位采集的深色碳质黏土岩（黑色页岩）中，产出了多样性极高、丰度丰富的提通期钙质超微化石组合。针对该样品的细致考察与归档记录工作，不仅拓展了诸多侏罗纪与白垩纪物种的化石延限范围，还详细刻画了钙质超微化石记录中显著的晚侏罗世化石组合更替事件。[…]